| 摘要 |
<p>932,588. Fluid-pressure servomotor control systems. SULZER FRERES S.A. Aug. 31, 1960 [Sept. 8, 1959], No. 30090/60. Class 135. In apparatus regulating the outlet temperature of medium flowing through a heat exchanger, an element influencing the medium entry temperature is controlled by a regulator responsive to outlet temperature and having at least an integral characteristic, the element receiving a preliminary impulse from a regulator responsive to the medium temperature intermediate entry and outlet but without an integral characteristic. Working fluid passes an injector 7 to a heat-exchanger, i.e. superheater 1, the temperature at the inlet, at an intermediate point and at the outlet being detected at 17, 21 and 19 to transmit negative pressure signals above piston 25 and positive below piston valve 28 and below piston 25, respectively, to move valve 28, servo-piston 11 and valve 9 controlling the supply of working fluid at 8 to injector 7 to regulate the outlet temperature, the signal from 19 having a proportional-integral effect by acting on the end of manually set piston valve 31 controlling pressure across piston 29 via restrictions 35 and also across spring-centred piston 38. The signal from 21 may provide a proportionalderivative effect. Flow, detected at 10 in line 8 or upstream of injector 7 sends a pressure signal to the upper end of piston valve 28 for maintaining a constant flow. The intermediate part of the superheater for detector 21 is protected from the furnace. The regulation may be effected electrically.</p> |
